Sealed Opening/Closing System for Packaging Bags

ABSTRACT

An opening/closing system, particularly for packaging bags, of the type that includes a planar base part defining at least in part an opening through itself, this base part includes guide means parallel to the opening and engaging with guide means belonging to a slider designed to close the opening or leave it open, which system is characterized in that, before the system is used for the first time, the opening is closed at least partly by a layer of material, and in that the slider includes a cursor directed toward the opening and capable of at least partly destroying the layer of material to open the opening when the slider is moved for the first time.

The present invention relates to an opening/closing system for packagingbags in particular.

Document FR 2 833 576 discloses the use of opening/closing systems forpackaging bags comprising a planar base part defining at least in partan opening through itself, this base part comprising guide meansengaging with guide means belonging to a slider capable of closing theopening or leaving it open, and the planar base part being designed tobe attached to the wall of the bag in such a way that the opening whichit defines coincides with an opening made in the wall of the bag.

This type of opening/closing system can in particular be attached to aprecut hole forming a strip designed to be torn off on first use. Thisprecut hole thus safeguards the bag because a user can immediately seewhether the bag has already been opened.

Experience shows, however, that this precut hole includes orifices whichmake a satisfactory seal difficult to achieve. In addition, theopening/closing system itself leaves an unsealed passage through itsopening.

Since a sealed bag is desirable for reasons of preserving its contents,for example, an additional device must then be applied, such as a bondedor welded detachable film. However, this type of device is situated onthe outside of the bag and can easily be damaged.

It is also prior art to use devices that destroy the actual wall of thebag in a region where there is no area of weakness. Documents U.S. Pat.No. 5,167,608, U.S. Pat. No. 6,652,436, U.S. Pat. No. 6,273,607 and EP 0485 741 may be cited in particular.

In the devices described in the documents cited above, cutting isdifficult because the wall is set back from the opening of the devicethrough which the cutting means passes. Moreover, the wall of the bagmust give it its strength is therefore resistant to being cut.

It is therefore an object of the present invention to provide anopening/closing system with an improved seal, without adding anyadditional external device to the bag and without making it moredifficult to use or to produce.

To this end, the subject of the present invention is an opening/closingsystem, particularly for packaging bags, of the type that comprises aplanar base part defining at least in part an opening through itself,this base part comprising guide means parallel to the opening andengaging with guide means belonging to a slider designed to close theopening or leave it open, which system is characterized in that, beforethe system is used for the first time, the opening is closed at leastpartly by a layer of material, and in that the slider comprises a cursordirected toward the opening and capable of at least partly destroyingthe layer of material to open the opening when the slider is moved forthe first time.

These provisions achieve the object indicated above. The layer ofmaterial can be of a predetermined strength so that it cuts easily, asit does not have to maintain the integrity of the bag. This layer ofmaterial is situated directly in the opening, an optimal position forcutting.

The layer of material is advantageously part of the same molding as thebase part.

In one embodiment the layer of material has an area of weakness where itis thinner.

The area of weakness advantageously extends approximately the fulllength of the opening.

In one embodiment, a housing for the cursor is provided in the layer ofmaterial, the dimensions of this housing being slightly less than thedimensions of the cursor, and the latter being force-fitted into thehousing.

The housing is advantageously situated at one end of the opening, andthe cursor faces this housing in the closed position of the cursor.

The present invention also relates to a packaging bag equipped on atleast one of its walls with an opening/closing system described above.

The opening/closing system is advantageously attached to the inside faceof one wall of the bag by the planar base part, the slide being situatedon that side of the planar base which is turned toward the wall, and thesystem being positioned in a precut hole formed in the wall.

The present invention also relates to a film for forming the walls of apackaging bag comprising at least one opening/closing system.

This film is advantageously presented in the form of a reel.

A clearer understanding of the present invention will be gained from areading of the following description with reference to the accompanyingdrawing showing an embodiment of an opening/closing device according tothe invention.

FIG. 1 is a partial view of a bag to which is attached anopening/closing system according to the invention.

FIG. 2 is a partial exploded perspective of an opening/closing systemaccording to the invention, in partial cross section.

FIG. 3 is a top view of the system shown in FIG. 2.

FIG. 4 is a cross section taken on IV-IV as marked in FIG. 3.

FIG. 5 is a cross section taken on V-V as marked in FIG. 3.

FIG. 6 is a view similar to FIG. 5, the system being shown during itsinitial opening.

FIG. 1 shows a bag 2 that has two walls 3 attached to each other, one ofthese walls 3 comprising an opening/closing system 4 attached to theinside side of an opening 5 in this wall 3.

This opening/closing system 4 can, as described in document FR 2 833576, be attached in a precut hole defining a band with rounded ends,which are cut out and can therefore be lifted and grasped to remove thisband by pulling it out by hand, removal of this band thus defining theopening 5 in the wall 3 of the bag 2.

The first time he uses it, a user can therefore remove the band bypulling it off, and then open and reclose the bag using theopening/closing system 4.

As shown more particularly in FIG. 1, the opening/closing system 4comprises a base part 7 defining at least in part an opening 8 throughitself, this base part 7 comprising guide means 10 parallel to theopening and engaging with guide means 12 in a slider 9 that can be usedto close the opening 8 or leave it open.

Before it is used for the first time, the opening 8 is closed by a layerof material 13 that is part of the same molding as the base part 7, asshown in FIGS. 2-6.

The slider 9 comprises a cursor 14 directed toward the opening 8 anddesigned to at least partly destroy the layer of material 13 in order toreveal the opening 8.

A housing 15 for the cursor 14 is provided in the layer of material 13,the dimensions of this housing 15 being slightly less than thedimensions of the cursor 14, and the latter being force-fitted into thehousing.

The cursor is situated at one end of the slider when the slider is inthe closed position of the opening 8, and the housing 15 is alsosituated at one end of the opening 8.

To facilitate the destruction of the layer of material 13 by the cursor14, the layer of material has an area of weakness 16 where it isthinner.

This area of weakness 16 extends approximately the full length of theopening 8.

The cursor 14 also serves advantageously as an end stop against theopposite end 17 of the opening 8 from that containing the housing 15, inorder to limit the range of movement of the cursor 14.

The layer of material 13 seals the opening 8. The housing 15 is slightlysmaller than the cursor 14 so that when the latter is forced into it itseals the housing 2, which can therefore be a through hole.

The cursor 14, in this embodiment, is in the shape of a parallelepipedwhich is easy to produce and allows good contact, and therefore a goodseal, with the walls of the housing 15. Other forms of this cursor maybe used as alternatives, notably beveled shapes to facilitate thedestruction of the layer of material 13. The shape of the housing 15will in this case be adapted to present a complementary shape.

In the embodiment shown, the slider has a tab 18 at each end for theuser to grip in the hand.

It is also possible to make the layer of material by adding it aftermanufacturing the base part. However, this considerably complicates themanufacture and increases the cost of this part.

FIG. 6 shows the destruction of the layer of material 13 when the system4 is opened for the first time.

It is advantageous to provide the film for forming the walls of apackaging bag with opening systems 4 described above before forming itinto the bags 3. In particular, the bag can be presented in the form ofreels which can then be used on known bag making machines.

It goes without saying that the invention is not limited to thepreferred embodiments described above by way of non-restrictive example;on the contrary, it encompasses all variants that come within the scopeof the following claims.

1. An opening/closing system, particularly for packaging bags, of thetype that comprises a planar base part defining at least in part anopening through itself, this base part comprising guide means parallelto the opening and engaging with guide means belonging to a sliderdesigned to close the opening or leave it open, which system ischaracterized in that, before the system is used for the first time, theopening is closed at least partly by a layer of material, and in thatthe slider comprises a cursor directed toward the opening and capable ofat least partly destroying the layer of material to open the openingwhen the slider is moved for the first time.
 2. The system as claimed inclaim 1, characterized in that the layer of material is part of the samemolding as the base part.
 3. The system as claimed in claim 1,characterized in that the layer of material has an area of weaknesswhere it is thinner.
 4. The system as claimed in claim 1, characterizedin that the area of weakness extends approximately the full length ofthe opening.
 5. The system as claimed in claim 1, characterized in thata housing for the cursor is provided in the layer of material, thedimensions of this housing being slightly less than the dimensions ofthe cursor, and the latter being force-fitted into the housing.
 6. Thesystem as claimed in claim 1, characterized in that the housing issituated at one end of the opening, and the cursor faces this housing inthe closed position of the cursor.
 7. A packaging bag equipped on atleast one of its walls with an opening/closing system as claimed inclaim
 1. 8. The bag as claimed in claim 7, characterized in that theopening/closing system is attached to the inside face of one wall of thebag by the planar base part, the slide being situated on that side ofthe planar base which is turned toward the wall, and the system beingpositioned in a precut hole formed in the wall.
 9. A film for formingthe walls of a packaging bag comprising at least one opening/closingsystem as claimed in claim
 1. 10. The film as claimed in claim 9,characterized in that it is presented in the form of a reel.